Woven wire fabric



April 3, 1956 s KN 2,740,601

WOVEN WIRE FABRIC Filed June 28, 1954 INVENTOR.

llgrf 5. Knapp United States Patent WOVEN WIRE FABRIC Albert S. Knapp,Worcester, Mass., assignor to G. F.

Wright Steel 8; Wire Co., Worcester, Mass, a corporation ofMassachusetts Application June 28, 1954, Serial No. 439,602

2 Claims. (Cl. 245-10) This invention relates generally to woven wirefabrics, and more particularly to woven wire fabrics of coarse or openmesh type, such as hardware cloth, wire lath or netting and the like.

The flexible wire used for such coarse mesh fabrics is invariably muchheavier in gauge than the wire used for fine mesh fabrics, such asscreen cloth, wire gauze and the like. Because of this, it has neverbeen practical, in the manufacture of these coarse mesh wire fabrics, tomake use of certain weaving techniques which give to fine mesh wirefabrics the woven-in selvage edges, longitudinally of the web, which arecharacteristic of various woven textile products.

That is to say, the usual machines for producing fine mesh wire fabricsemploy (in similar fashion to a textile weaving machine) a transverselyreciprocating shuttle, the latter carrying in coiled or spooled form, asupply, in great length, of the fine gauge Wire which provides the finemesh fabrics continuous weft and which, at each shuttle reversal, isincorporated in a finished selvage, along both sides of the web.However, since such a weft supply shuttle can carry only a very limitedlength of the much heavier gauge wire used in coarse or open meshfabrics, it is neither practical nor economical to produce coarse meshfabrics in this fashion, because of need for frequent machine shutdownsto replenish the shuttles weft supply.

Instead, it has long been common practice, in manufacturing these coarsemesh wire fabrics, to supply the weft, not in the above describedcontinuous fashion from a reciprocating shuttle, but rather by asuccession of individual relatively short wires which are projected oneafter another across the set of spaced parallel Wires, always heretoforeof uniform circular cross section, that provide the longitudinallyadvancing warp components of every such coarse mesh wire fabric. To giveto a coarse mesh wire fabric made in this non-stop fashion, the requiredlongitudinal selvage edges, it was the practice many years ago (seeScarles Patents Nos. 345,735 and 355,561) to interloop or twist togetherthe projecting ends of the individual transverse weft wires; thisprovided the fabric, beyond each of its outermost warp wires, with acontinuous selvage edge. But the latter, because of its thickness, wasunduly resistant to the bending, flexing, rolling and the like, whichevery such fabric, in ordinary use, must undergo.

Selvage edges of these patented Scarles types, for coarse mesh wirefabrics, were rendered practically obsolete by the advent of spotwelding, which made it very easy for each individual transverse weftwire (see Sommer Patent No. 1,783,948) to be rigidly connected with thefabrics two outermost warp wires, so that with subsequent cutoff of theweft wires projecting ends, these outermost warp wires would serve asthe longitudinal selvage edges of the fabric. But welded selvage edgesas disclosed in the aforesaid Sommer patent are invariably crude andunsatisfactory from two standpoints, viz.: (1) because every cutoff weftwire always presents, just beyond its weld,

a sharp edge or burr, as a constant hazard to the hands and clothing ofanyone working with the fabric, and (2) because each outermost warpwire, from pressure of the welding electrodes, is oftentimes subject tooutward lateral deflection into the fixed plane of weft wire cutoff,with resulting severance or weakening of the so-welded selvage edgewhenever such a deflection occurs.

Efforts made heretofore to obtain more satisfactory and reliable weldedselvage edges for these coarse mesh wire fabrics have introducedexpensive complications; see for examplethe fabric of Harter Patent No.2,024,796, which requires that each individual transverse weft wire beextended beyond a holding weld to the fabrics outermost warp wire, topermit of its being bent over against and welded to the next adjacent(and similarly bent) transverse weft wire.

My invention, eschewing such and similar complications, has as itsprimary object the provision of welded selvage edges for coarse meshwire fabrics, in the simple fashion of the aforesaid Sommer patent, butwithout the disadvantages (1) and (2) above of the Sommer con struction.

Other and further objects and advantages of my invention will beapparent from the following detaileddescription thereof, taken inconnection with the accompanying illustrative drawings in which Fig. 1is a plan view of the coarse mesh wire fabric of my invention, andshowing schematically, from right to left, the successive steps involvedin the formation ofits novel welded selvage edges.

Fig. 2 is a corresponding schematic view in side elevation.

Fig. 3 is a framentary view, on a greatly enlarged scale, illustratingthe favorable coplanar relation of the connected parts, along eachwelded selvage edge of my invention.

Fig. 4 is a large scale sectional view illustrating, by comparison withFig. 3, the unfavorable edge conditions that are created by said Sommerpatents utilization, for welded selvage edge purposes, of theconventional outside longitudinal warp strand of a coarse mesh wirefabric.

Referring first to Figs. 1 and 2, the illustrated fabric is made byinterweaving, in conventional manner, a succession of spaced transverseround wires 1, 1, with a set or series of similarly spacedlongitudinally advancing warp wires; the latter, as here shown, includea plurality of the usual round wires 2, 2 preferably of the same gaugeas the wires 1, 1, and also, along each side of the fabric, outwardly ofsaid round warp wires 2, 2, a single fiat wire 3 of thin strip form,whose substantially rectangular cross section has a relatively highwidth-tothickness ratio.

Each flat warp wire 3 is disposed fiatwise in the plane of the fabric,and each has a thickness which is no greater, in any case, than thediameter of the companion circularsection Warp wires 2, 2; thus said twooutside warp wires 3, 3 are not unduly resistant to the bending, flexingand rolling of the completed wire fabric, nor to the conventionalweaving operation by which said fabric is formed.

In said weaving operation, these two outside warp wires 3, 3, advancingfiatwise, preferably partake, along with the intermediate round warpwires 2, 2, of the usual repeated shed formations through which thesuccessive filling or weft wires 1, 1 are projected, as by way of asuitable guide tube 4, Fig. 2. As a result of this conventionalinterweaving, the round weft wires 1, 1, upon emergence from the shed,have the usual alternate over and under crossed relation with saidoutside fiat wires 3, 3, and have their ends projecting slightly beyondsaid outside flat wires 3, 3, as shown at 5, 5, Fig. l.

The next operation, performed by suitably timed electrodes 6, 6 aboveand below the path of each flat wire 3,

is to produce a weld at each place where the successive filling Wires 1,1 cross each of the flat outside warp wires 3, 3 as indicated at 7, 7 onthe drawings.

The final step in the manufacture of my improved wire fabric is to cutoff the projecting ends 5, 5 of each sowelded round weft wire 1, i, bythe suitably timed operations of a pair of oscillatory cutters 8, S,flanking the flat wires 3, 3, and each providing a blade 9 whosemovement is, for all practical purposes, in the same vertical plane asthat occupied by the thin outer face 1% (see Fig. 3) of the associatedflat wire 3.

It is to be particularly noted, in the case of each flat outside warpwire 3, that the latters inherent very high resistance to lateraldeflection, in the plane of the fabric, from pressure of electrodes 6,6, makes it practically impossible for said wires outer face it? todeviate in even the slightest degree from the aforesaid fixed verticalplane in which the associated cutter blade 9 is operative. Therefore, bythe successive operations of the cutters 8, 8, the

projecting ends 5, S of all of the weft wires 1, 1, are so sheared oi,as to leave the latter, in every case, substantially flush (i. e.coplanar), as shown at 11, Figs. 1 and 3, with each flat wires thinoutside face 10. This gives along each side of the completed fabric awelded selvage edge construction which, because of the width of the flatwire 3, is desirably very resistant to lateral bending or sagging in theplane of the fabric. Furthermore, the outside surface (Fig. 3) of eachwelded selvage edge is uniformly smooth and continuous, and presents nosharp projections of a character that might cause injury to the hands ofanyone working with the fabric.

Such would not be the case, were the so cut-oti weft or filling wires 1,1 welded to an outer longitudinal or warp wire 12 (Fig. 4) of thecustomary round cross section shown in the aforesaid Sommer patent. inthat situation, every such cut-oft" weft wire 1, 1, along both sideedges of the fabric would present, adjacent its weld, a sharp corner oredge 13, Fig. 4, as a constant hazard to the hands of anyone workingwith the fabric.

Furthermore, such a round outermost warp wire (see 12 Fig. 4) has suchlow resistance to sidcwise or horizontal deviation, that portions ofsame from pressure of the 4 welding electrodes, can be and are inpractice very easily deflected into the fixed vertical plane path of thecut-0E blades; in any such case a welded selvage edge of the Sommerconstruction shown by Fig. 4 would be partially severed, and the fabricas a whole materially weakened.

I claim:

1. An open mesh wire fabric of the class described, including a set ofspaced parallel longitudinal warp wires of uniform circular crosssection, a succession of spaced transverse filling or weft wires ofsimilar cross section disposed in crossed relation to said warp wiresand projecting at both ends therebeyond, and a pair of outermostflexible warp wires along each side of said set and also crossed by saidweft wires, said two outermost warp wires being of flat strip formdisposed flatwise in the fabrics plane, and of a thickness no greaterthan the diameter of said circular-section warp wires, with said weftwires spot welded at their points of crossing to said two outermost fiatsection warp wires and sheared olf in coplanar relation with the lattersthin outside faces.

2. A open mesh wire fabric of the class described, in

cluding a set of spaced parallel longitudinal warp wires of uniformcircular cross section, a succession of spaced transverse filling orweft wires interwoven in over-andunder relation with said warp wires andprojecting at both ends therebeyond, and a pair of outermost flexiblewarp wires along each side of said set and also crossed by said weftwires, said two outermost warp wires being of flat strip form disposedflatwise in the fabrics plane, and of a thickness no greater than thediameter of said circular-section warp wires, with said weft wires spotwelded at their points of crossing to said two outermost flat sectionwarp wires and sheared off in coplanar relation with the latters thinoutside faces.

References Cited in the file of this patent UNITED STATES PATENTS945,616 Schwartz Jan. 4, 1910 1,783,948 Sommer Dec. 2, 1930 2,024,796Harter Dec. 17, 1935 2,315,055 Heller Mar. 30, 1943

